The new machine, by contrast, turns multiple nanotube emitters on and off in sequence to take pictures from different angles without moving. Because the emitters turn on and off instantaneously, says Daniel Kopans, director of breast imaging at Massachusetts General Hospital, the system should be able to take more images every second. This faster exposure, Kopans says, should reduce blur, much as a high-speed camera captures ultrafast motion. Zhou and his colleagues have been able to take breast images at nearly twice the resolution of commercial scanners, using 25 simultaneous beams in a few seconds.
Fast, real-time imaging will in turn improve cancer treatment. “State-of-the-art radiation therapy is highly image-based,” says Sha Chang, a professor of radiation oncology at the UNC School of Medicine who is working with Zhou. Pictures of the tumor area are taken so that radiation can be focused on the tumor, sparing the normal tissue surrounding it. But since today’s scanners are slow, Chang says it isn’t possible to take 3-D images and treat the patient at the same time. “Using the [nanotube] x-ray imaging device allows [us] to collect 3-D imaging while we’re treating the patient, to make sure high-dose radiation and heat [are] delivered to the right place,” she says.
The clinical test results will determine if Xintek can enter the medical-imaging market. Meanwhile, the company is also selling its nanotube emitters to display manufacturers. Companies such as Samsung and Motorola are making displays based on nanotube emitters that promise to consume less power than liquid-crystal displays or plasma screens while providing the brightness and sharpness of bulky cathode-ray-tube TVs because they work on the same principle: shooting electrons at a screen coated with red, green, and blue phosphors.
Xintek’s imaging technology is also proving useful for research on laboratory animals. It can take sharp cardiac images of mice, which is hard because of their rapid heartbeats. Zhou says that biomedical researchers at UNC are already using the system and are installing a second unit at the medical-school research facility.